Diazo-type multicolor reproduction

ABSTRACT

A PROCESS FOR THE DIAZO-TYPE MULTICOLOR REPRODUCTION BY WHICH PORTIONS OF A SENSITIVE PAPER CORRESPONDING TO PREDETERMINED PORTIONS OF AN ORIGINAL CAN BE SELECTIVELY COLORED TO DIFFERENT HUES BY DISPOSING A LAYER OF THERMOTRANSFERABLE COUPLER BETWEEN AN ORIGINAL AND DIAZO-PHOTOSENSITIVE PAPER FOLLOWED BY EXPOSURE TO LIGHT AND HEATING OF THE ASSEMBLY. THE LAYER OF THERMOTRANSFERABLE COUPLER IS NOT APPLIED TO THE ENTIRE IMAGE AREA OF THE ORIGINAL AND THE THERMOTRANSFERABLE COUPLER IS FASTER IN COUPLING RATE WITH THE DIAZONIUM SALT UNDER THE DEVELOPMENT CONDITIONS THAN THE BASIC COLOR COUPLER OF THE PHOTOSENSITIVE PAPER OR DEVELOPING SOLUTION.

1973 KOUZI NIHYAKUMEN L DIAZO-TYPE MULTICOLOR REPRODUCTION Filed Feb. 17 1970 4 Sheets-Sheet l PREPARAUON OF OR\G\NN. FOR MUL'HCOLOR DEVELOPMENT PREPARMWON OF OmGnNAL FOR MULUCOLOKZ DEVELOPMENT 1 COUPLER 1 SHEET FOR 3 TRANSFERYU NG COUPLER new UGHT H6 4 sourzce Hm F7524 sourzca HEAT 9) scjce g S S HZCE a H PHOTOSENSVYWE BASE PHOTOSENSUVE LAYER Fob. 6, 1973 KOUZI NIHYAKUMEN ET A1. 3,715,213

DIAZO-TYPE MULTICOLOR REPRODUCTION 4 Sheets-Sheet 2.

Filed Feb. 17 1.970

Feb. 6, 1973 Kouz MHYAKUMEN ETAL 3,715,213

DIAZO-TYPE MULTICOLOR REPRODUCTION Filed Feb. 17 1970 4 Sheets-Sheet 3 Feb. 6,1973 Kouz NlHYAKUMEN ETAL 3,715,213

DIAZO-TYPE MULTICOLOR REPRODUCTION Filed Feb. 17 1970 4 Sheets-Sheet 4 \KC \8\/ 23 "l n y le CHRNGEOVER 5W\TCH 7 HEAT \JGHT $OUQCE SOURCE VOLTAGE ADJUST ER COOUNG T MECHAWSM l A V Y SECTOR CYUNDER TEMPERATURE smss DET EcT\oN TEMPERATURE CONTROL I l DELNERY coo UNG BELT *"MEcHmTsM J United States Patent 3,715,213 DIAZO-TYPE MULTICOLOR REPRODUCTION Kouzi Nihyakumen and Taizo Yokoyama, Osaka, Yasuo Ueda, Kobe, and Yasutoki Kamezawa and Tatsuo Aizawa, Osaka, Japan, assignors to Mita Industrial Company Limited, Osaka, Japan Filed Feb. 17, 1970, Ser. No. 12,049 Claims priority, application Japan, Feb. 19, 1969, i i/11,914; Aug. 22, 1969, 44/65,980; Nov. 18, 1969, 44/931,964

Int. Cl. G03c 5/18, 1/58 U.S. C]. 96-49 12 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the diazo-type multicolor reproduction. More specifically, it relates to a process for the diazo-type multicolor reproduction by which portions of a sensitive paper corresponding to predetermined portions of an original can be colored selectively to diiferent hues.

It has been heretofore known that when two or more diazonium salts which have different resolving rates and exhibit different hues upon bonding with couplers are used in the diazo-type reproduction, reproductive copies can be obtained which are colored in two or more hues depending on the intensity of light on the exposed portions. In such reproductive copies, image colors of the has a higher coupling rate under developing conditions than coupler (b).

(II) Dyestuff (b)-(c), dyestuff (a)-(c), dyestuif (a')(c) formed at the development have hues different from one another.

Any coupler that can be volatilized or sublimated by heating and be coupled with a photosensitive diazonium salt may be used as the thermovolatile or thermosulzlimative coupler (a) in this invention. As such coupler (a) phenol derivatives, hydroxynaphthalene derivatives, aniline derivatives and active methylene group-containing compounds may be mentioned. It is generally preferred that these derivatives do not contain soluble groups such as a sulfonic acid group for the purpose of facilitating the heat transfer operation.

Examples of these derivatives usable as coupler (a) are as follows:

Phenol derivatives Phenol Pyrocatechol semi-exposed portions are mingled with image colors of non-exposed portions to form a compound color, and the color contrast in the image becomes faded. Further, in such known reproduction process it is impossible to reproduce an original having a similar image concentration or light transmission throughout the entire original, into different hues.

No diazo-type reproduction process has been known by which predetermined portions of an original can be produced into hues different from one another regardless of difference or similarity of the light transmission in the original.

It has now been found that predetermined portions of an original can be reproduced into different hues regardless of the difference or similarity of the light transmission in the original by conducting the steps of (A) exposing to light a diazo-type photosensitive material containing at least one diazonium salt and (B) heating a layer of at least one thermovolatile or thermosublimative coupler (a) disposed in face-to-face contact with a predetermined portion of the diazo-type photosensitive material, the steps being carried out coincidentally or in an order of (A) to (B) or (B) to (A), and then developing the exposed photosensitive material in the presence of a coupler (b) having a lower coupling rate under developing conditions than the thermovolatile or thermosublimative coupler (a).

It is essential that among the thermovolatile or thermosublimative coupler (a), coupler (b) and diazonium salt (0) used in this invention there should be established the following relations:

(I) Thermovolatile or thermosublimative coupler (a) Resorcin Phloroglucinol o-Hydroxybenzalcohol Resorcin monoglycol ether Resorcin glycol ether Hydrotholuquinone Pyrogallol-4-carboxylic acid Vanillin Isovanillic acid Vanillic acid S-hydroxy-isophthalic acid 2-hydroxy-terephthalic acid 2-hydrxy-p-toluylic acid 3-hydroxy-p-toluylic acid S-hydroxy-o-toluylic acid 6-hydroxy-m-toluylic acid S-hydroxy-l-naphthonic acid Para-hydroxyphenylacetic acid Para-hydroxybenzaldehyde Ortho-hydroxybenzoic acid Ortho-hydroxybenzyl alcohol 4,4-dihydroxybiphenol 3,5-dichloro-salicylic acid S-chloro-Z-nitrophenol 2,S-dihydroxyacetophenone 2,5-dinitrophenol 2,4-dinitrophenol 2,4-dinitroresorcin 4,6-dibr omo-2-nitrophenol 2,S-dimethyl hydroquinone Hydroxynaphthalene derivatives 2,3-dihydroxynaphthalene fi-Naphthol a-Naphthol 1,6-dihydroxynaphthalene 2,6-dihydroxynaphthalene 2,7-dihydroxynaphthalene S-amino-Z-naphthol 2,2'-dihydroxy-1,1'-binaphthyl 4,4'-dihydroxy- 1, 1'-binaphthyl 3-carboxy-2-naphthol Aniline derivatives Meta-aminobenzoic acid 2-amino-p-cresol Ortho-aminophenol Para-aminophenol Para-chloroaniline 3,4-diaminoto1uene Active methylene group-containing compounds 1-phenyl-3-methylpyrazolone 1-phenyl-3-carboxypyrazolone Acetoacetic acid anilide Acetoacetic-o-chloroanilide As coupler (b) to be used in combination with the above-mentioned coupler (a) in conducting the process of this invention, any coupler may be used as long as it has a lower coupling rate under the same developing conditions than coupler (a) actually used. In case a plurality of thermovolatile or thermosublimative couplers (a) are used, the coupling rate of coupler (b) should be lower than that of any of couplers (a). Selection of couplers (a) and (b) meeting the above requirements may be easily performed by those skilled in the art based on a simple experiment.

In addition to those having relatively low coupling rates among the above exemplified couplers, the following compounds may be used as coupler (b):

Phenol derivatives 2,5,6-trimethylphenol Z-hydroxymethylphenol ,8-(2-hydrovypheny1)-propionic acid 2-( w-phenylaminomethyl) -pheno1 fi-(4-methyl-2-hydroxyphenyl)-glutaric acid 2,5-dimethyl-6-(N-dimethylaminornethyl)-phenol 1,3-dimethyl ether of pyrogallol N-lauryl-p-aminophenol N-acyl-m-aminophenol Meta-hydroxy-acetoanilide Ortho-N-hydroxyphenyl-monoguanidine Para-N-hydroxyphenyl-biguanidine 2,5-dimethyl-4-morpholinomethyl phenol Z-methyl-S-isopropyl-morpholinomethyl phenol 4rnorpholinomethylresorcinol monomethyl ether 3,3',5-trihydroxydiphenyl 3,3',5,5'-tetrahydroxydiphenyl 2,2',4,4-tetrahydroxydiphenyl, 2,4,4-trihydroxydiphenyl-2'-sulfonic acid 2,4,6,3',5-pentahydroxydiphenyl 2,2,4,4'-tetrahydroxydiphenyl sulfide Naphthols 2,3-dihydroxynaphthalene-fi-sulfonic acid 2-naphthol-3,6-disulfonic acid 2,7-dihydroxynaphthalene-3-sulfonic acid 2,8-dihydroxynaphthalene-6-sulfonic acid 1,8-dihydroxynaphthalene-8-sulfonic acid 1-8-aminonaphthol-S-sulfonic acid 2,7-dihydroxy-3,6-disulfonic acid 1,8-benzoylaminonaphthol-2-sulfonic acid 1,8-dihydroxynaphthalene-6-sulfonic acid Z-hydroxy-3-naphthionic-N-B-hydroxyethyl amide Z-hydroxy-3-naphthionic-N,N-bis-B-hydroxylether amide 8-hydroxy-Z-naphthionic-hydroxyethyl amide 1-(N-carboethoxymethylamino)-8-naphthol-4-sulfonic acid S-(para-nitro)-benzamido-1-naphthol 1-hydroxynaphthyl-7-phenyl-guanidine 2-hydroxynaphthyl-8-biguanidine 1-naphthol-3-(N-fi-hydroxyethyl)-sulfonic amide 1-naphthol-3- (N-o-methoxyphenyl)-sulfonic amide Bis- [5-hydroxy-7-sulfo-naphthyl (2) J-amine N,N-bis l-hydroxy-3-sulfo-naphthyl (6) J-thiourea Active methylene group-containing compounds Acetoacetic acid cyclohexylamide Acetoacetic acid benzylamide Cyanoacetoanilide Cyanoacetomorpholine Heterocyclic compounds 1- (3 -sulfo amide) -phenyl-3-methylpyrazolone-5 1- (4'-carboxy-ethylphenyl -3-dodecyl-pyrazolone-5 8-hydroxy-1,2-naphthylimidazole 2-methyl-4-hydroxybenzimidazole 7-methyl-4-hydroxybenzothiazole 1,7-dimethyl-4-hydroxy-benzotriazole 3-hydroxythiophene-S-carboxylic acid 1-3-4-cyclopentatrione In conducting the process of this invention, at first an original for multicolor development is formed by applying at least one transparent or semi-transparent layer of a thermovolatile or thermosublimative coupler (a) onto the back surface of one or more predetermined portions of a transparent or semi-transparent original to be reproduced. The so formed original for multicolor development is overlapped on a diazo-type photosensitive material containing at least one diazonium compound (c) in a manner such that the layer of coupler (a) will confront the photosensitive surface of the photosensitive material, and the lightexposure and heating are eflected coincidentally with the above overlapping or after such overlapping. Thus, the thermovolatile or thermosublimative coupler (a) is heattransferred to the surface of the predetermined portion of the photosensitive material, and the light resolution of the diazonium salt (c) in the photosensitive material is caused to occur depending on the light transmission. When the so exposed photosensitive material is developed by a method known per se, at the predetermined portion to which the coupler (a) has been heat-transferred, the diazonium salt (c) at the non-exposed area is selectively reacted with the coupler (a) to form a dyestuff (c)(a) and at other portion the diazonium salt (c) at the nonexposed portions is reacted with coupler (b) to form a dyestuff (c)-(b). Thus, a multicolored reproductive copy in which the predetermined portion is colored in a hue different from that of the other portion is'obtained.

The above-mentioned original for multicolor development may be prepared, for instance, by a method comprising applying a coating composition containing the above-mentioned thermovolatile or thermosublimative coupler (a) onto the back surface of a portion predetermined to have a dififerent hue, of a transparent or semitransparent original, or by a method comprising coating or impregnating a transparent or semi-transparent sub strate with the coating composition and combining the resulting sheet for heat-transferring the coupler with the back surface of the specific portion of the original predetermined to have a difierent hue in a manner such that the layer for heat-transferring the coupler will confront the photosensitive material.

A coating composition for treating the back surface of an original and forming a layer for heat-transferring the coupler can be easily prepared by dispersing a coupler (a) into a liquid, semi-solid or solid dispersion medium.

Such treating agent will be now described by referring to some embodiments.

(l) Ink-like composition for treating the back surface of an original:

Percent Coupler (a) 5.0-25.0 Coloring material 0-3.0 Binder 0-5.0 Dispersion assistant 0-2.0 Dispersion medium Balance As the dispersion medium water and organic solvents such as alcohol, toluene, xylene, esters and methyl ethyl ketone may be used. It is possible to incorporate a coloring material so as to confirm the formation of a film of the treating agent, or to use a binder for the purpose of obtaining a good fixation of the coupler.

The composition of the above recipe is applied to the back surface of a portion predetermined to have a different hue by means of a brush, an installed felt pen, a ball pen, a coating roller, 2. sprayer or a printing machine.

(2) Waxy composition for treating the back surface of an original:

Percent Coupler (a) 5.0-25.0 Wax 85.0-15.0 Oil 10.0-40.0 Coloring material -20.0

The composition of the above recipe is shaped to have a crayon stick-like form or a chalk-like form, and the back surface of a portion of an original predetermined to have a different hue is painted therewith. It is also possible to form a pressure-sensitive transfer sheet by melting the above composition or dissolving it in a suitable solvent and coating the melt or solution on a substrate such as paper and plastic film. The so-formed pressure-sensitive transfer sheet is overlapped on the back surface of an original sheet, and then pressing is effected thereon by means of a typewriter or other writing means to form a heat-transferable layer on the back surface of an image predetermined to have a different hue.

(3) Coupler-transferring sheet for treating the back surface of an original The ink-like composition for treating the back surface of an original, which was described in (1), or a composition obtained by incorporating a binder or an extender into such ink-like composition is coated on a transparent or semi-transparent sheet such as paper, plastic film or non-woven fabric. The so formed sheet for heat-transferring the coupler is cut into a desired size, if necessary,

- and then applied to the back surface of a portion of an original determined to have a different hue. It is possible to form a pressure-sensitive adhesive layer on the back surface of the coupler-transferring layer for preventing it from exfoliating from the original.

The original for multicolor development prepared with the use of the above-mentioned agent for treating the back surface of an original to be reproduced may be generally used 5 to 100 times repeatedly for the multicolor development, though the applicable frequency of the repeated use varies depending on the amount coupler (a) coated, the coating method, the heating method and the developing method. Of course, when the heat-transferability of coupler (a) in the layer for heat-transferring the coupler is lowered, it is sufficient to supply an additional layer for heat-transferring the coupler.

The above-mentioned original for multicolor devevlopment is overlapped on the photosensitive material in a manner such that the coupler-transferring layer applied on the original will confront the photosensitive surface of the photosensitive material, and the exposure and heating are effected.

Various photosensitive materials containing a diazonium salt are used in this invention according to the developing method. They are usually formed by coating a sensitizing composition containing a diazonium compound and, if necessary, a coupler (b) on a substrate such as paper, plastic film, fibrous fabric, non-woven fabric and metal foil. Such photosensitive material will be now described by referring to only a few examples.

(A) Sensitizing composition for dry development:

Percent Azo coupling component (b) 0.2-5.0 Diazo compound 0.2-5.0 Organic acid 0.1-5.0 Coloring matter 0.001-0.025 Development promoter 1.0-10.0 Extender 0-2.5 Solvent Balance The sensitizing composition of the above recipe is coated on a substrate such as paper and plastic film, and dried to form a photosensitive sheet.

(B) Two-component type sensitizing composition for wet development:

Percent Azo coupling component (b) 0.2-5.0 Diazo compound 0.2-5.0 Organic acid O.15.0 Stabilizer 05.0 Extender 0-2.5 Coloring matter 0.001-0.025 Solvent Balance The sensitizing composition of the above receipe is coated on a substrate such as paper and plastic film, and dried to form a photosensitive sheet.

(C) One-component-type sensitizing composition for wet development:

Percent Diazo compound O.2-5.0 Organic acid 0.1-5.0 Extender 0-2.5 Coloring matter 0.00l-0.025 Solvent Balance The sensitizing composition of the above recipe is coated on a substrate such as paper, and dried to form a photosensitive paper.

Any diazonium compound that is capable of being coupled with the above-mentioned couplers (a) and (b) under ordinary developing conditions may be used as the diazonium compound (0) in this invention. Examples of such diazonium compound are as follows:

Para-phenylene-diarnine-N,N-substituted compounds of the following general formula:

N-Q-NZ X RI! wherein X stands for an anion, R and R" each are aliphatic groups, and Z and Y denote groups which can be introduced into the benzene nucleus.

Specific examples of the compounds of this type are as follows:

Aminohydroquinone ether-type compounds of the following general formula:

| RI! OR wherein R, R and R" are alkyl or aryl groups and X stands for an anion.

Specific examples of the compounds of the above type are as follows:

4-diazo-2,5-dibutoxy-N,N-diethylaniline 4-diazo-2,S-diethoxy-N-benzoyl aniline (referred to simply as BB salt) 4-diazo-2,5-diethoxy-N-ethyl-N-benzoyl aniline 4-diazo-2,S-dibenzyloxy-N-benzoyl aniline 4-diazo-2-chloro-Sunethoxy-N-benzoyl aniline 4-diazo-2,Sdiethoxy-N-benzoyl-methyl aniline 4-diazo-2,5-diethoxy-N-benzoyloxy-methyl aniline Other 4-diazo-2,5-dioxyalkyl (or dioxyaryD-N-alkyl (r aryl) compounds and derivatives thereof Aminodi-phenyl compounds, aminodiphenyl amine compounds and their analogues of the following general formulas:

wherein X is an anion, R is a divalent aryl group, R is a monovalent or divalent aryl or alkyl group, A is a divalent group or a direct bond and examples of the RAR' are diarylamine (A; NH--), diphenyl (A; direct bond), diphenyl oxide (A; O-), diaryl methane (A; CH stilbene (A; CH=CH) and diaryl or dialkyl sulfide (A; S).

Specific examples of the compounds of the above type are as follows:

Para-diazophenyl amine 4diazo-2,5,4'-triethoxydiphenyl amine 4-diazo-2,5,4'-triethoxydiphenyl 4,4'-bis-diazo-2,2',5,5-tetrahydroxyphenyl methane Bis-diazo-S,8'-dichloro-5,5dimethoxy benzidine 4-diazo-2,S-dimethoxyphenylethyl sulfide 4-diazo-2,5-diethoxy-4methyl-diphenyl sulfide Heterocyclic amine derivatives of the following general formula:

/O Hrogz wherein X stands for an anion, Y and Z are groups which can be introduced into the benzene nucleus, and A is a direct bond or a divalent group such as O, S and methylene. Specific examples of the compounds of this type are as follows:

4-diazo-2,S-dibutoxy-N-phenyl morpholine 4-diazo-2,S-diethoxy-N-phenyl morpholine 4-diazo-Z-methoxy-N-thio morpholine 4-diazo-N-phenyl piperidine 4-diazo-N-phenyl pyrrolidine 4-diazo-2,S-di-n-butoxy-N-phenyl piperidine Other derivatives of 4-diazo-N-phenyl heterocyclic amines.

N,N-substituted ortho-phenylene diamine derivatives and orthoamino-phenol derivatives.

Specific examples of the compounds of this type are as follows: 2-diazo-4-methylmercapto-N,N'-dimethyl aniline 2-diazo-5-benzoylamino-N,N-dimethyl aniline 2-diazo-l-naphthol-S-sulfonic acid The above-mentioned diazonium compounds may be used in the form of a relatively stable salt with sulfuric acid or hydrochloric acid. They may also be used in the form of a double salt with zinc chloride, tin chloride, aluminum sulfate or the like. Further, they may be used in the state stabilized by an aryl sulfonate (in the form of a diazonium salt of an aromatic sulfonic acid), a diazosulfonate or the like.

The exposure of the photosensitive material and the transfer of the thermovolatile or thermosu'blimative coupler (a) to the photosensitive surface may be effected coincidentally. For instance, in case a mercury lamp is used as light source for exposure, the heat transfer of the coupler (a) may be effected coincidentally with the exposure by the heat conveyed through a cylinder glass of the light source maintained at a relatively high temperature. Of course, the heat transfer of the coupler (a) may be also effected by the radiation heating of an image of the original. The heat transfer of the coupler (a) may be effectively performed by heating the layer for heat-transferring the coupler at a temperature above 50 C., preferably above 70 C., though a preferable heating temperature varies to some extent depending on the kind of the coupler (a) and the heating time. It is also possible to adopt to a method comprising piling the above-mentioned original for multicolor development and the photosensitive material, passing the assembly through a heated roller of an infrared radiation zone to heat the layer for heattransferring the coupler at the above-mentioned temperature and to effect the heat transfer of the coupler, and then passing the same through an exposure zone to effect the exposure of the photosensitive material.

It is also possible to adopt a method in which the exposure and heat transfer are conducted in an order reverse to that of the above method, namely a method comprising piling the original for multicolor development and the photosensitive material, passing the assembly through an exposure zone to effect the exposure of the photo sensitive material and then passing the same through a heating zone to effect the heat transfer of the coupler (a).

In accordance with this invention, the photosensitive material which has been exposed to light and on a predetermined portion of which the coupler (a) has been heat-transferred, is developed in the presence of a coupler (b) by means known per se. It is possible to incorporate the coupler (b) in the photosensitive material in ad vance, or to incorporate the coupler (b) in a developer. The development may be conducted by either a dry method or a wet method.

In accordance with the dry method, the development may be performed suificiently only by exposing the lightexposed photosensitive material to a mixture of ammonia and steam. The development of a one-component-type photosensitive paper in use for the dry method may be carried out by coating a liquid developer having, for instance, the following recipe, on the photosensitive material by dipping, roller coating or spraying:

Percent Coupler (b) 0.25 Alkali 0.5-10 Reducing agent 020 Surface-active agent 0 O.5 Water Balance In the case of a two-component-type photosensitive paper in use for the wet method, the development is achieved by contacting the photosensitive paper with an aqueous liquid developer containing an alkali.

Thus, in accordance with this invention multicolored reproductive copies in which the predetermine portion is colored by a dyestuff formed of coupler (a) and diazonium salt (0) and the other portion is colored by a dyestuff formed by coupler (b) and diazonium salt (c) can be provided.

This invention will be detailed by referring to accompanying drawings.

FIGS. 1 and 2 are given to explain the principles of light exposure, heat transfer and development in the apparatus of this invention. FIG. 3 is a sectional diagram showing one embodiment of the apparatus of this invention. FIGS. 4 and 5 are views illustrating embodiments of the arrangement of a light source and a heat source. FIGS. 6 and 7 are views illustrating embodiments of the development mechanism. FIGS. 8 and 9 are views showing embodiments of the apparatus of this invention. FIG. 10 is a block diagram illustrating a control system to be adaptable to the apparatus of this invention.

The principle of the apparatus is first described. In FIG. 1, different thermovolatile or thermosublimative couplers 2 and 3' are coated on the back surfaces of images 2 and 3, respectively, of an original having images 1, 2 and 3. When the so formed original for multicolor development is overlapped on a photosensitive paper, and exposed to light emitted from a suitable light source, latent images 1", 2" and 3 corresponding to images 1, 2 and 3 are formed on the photosensitive layer and couplers 2' and 3' are transferred on the upper surface of the photosensitive layer. When the above photosensitive sheet is developed, the diazonium salt in latent images 2" and 3 of the photosensitive layer is selectively reacted with transferred couplers 2' and 3', while the diazonium salt in latent image 1" is reacted with a coupler contained in the photosensitive layer. Thus, a reproductive copy which has images 11, 12 and 13 colored in different hues is obtained.

FIG. 2 is a view illustrating an embodiment similar to the above embodiment shown in FIG. 1, except that a heat-transferable sheet containing coupler 2 and another heat-transferable sheet containing coupler 3' are applied to the back surfaces of images 2 and 3, respectively.

The process of this invention can be performed by the following apparatus, namely, an apparatus for the diazotype multicolor reproduction which comprises a light source for exposing a diazo-type photosensitive material to light; a heat source for transferring a thermovolatile or thermosublimative coupler from a layer of coupler to a photosensitive layer of the photosensitive material on which the coupler layer is overlapped; a developing mechanism for developing the light-exposed photosensitive material on which the coupler has been heat-transferred; and a delivery mechanism for feeding the diaZo-type photosensitive material, the thermovolatile or thermo sublimative coupler layer and the original to a device for subjecting them to actions of the light source and heat source while maintaining them in the overlapped state and contacting them with such device, and feeding only the light-exposed and heat-transferred photosensitive material to the development mechanism.

Any light source that can emit a light of a wavelength sufficient to resolve the diazonium salt in the photosensitive material may be used as a light source of the apparatus of this invention. A fluorescent lamp, a low voltage or high voltage mercury lamp, a xenon lamp, an arc lamp or an incandescent lamp may be optionally used. It is preferable that such light sources are contained in a rotatable transparent cylinder, so that the diazo-type photosensitive material is exposed to light in close contact with the original. In case a light source is provided in a transparent cylinder, a suitable cooling mechanism may be provided to cool the light source and transparent cylinder to suitable temperatures.

Any heat source that can heat-transfer a thermovolatile or thermosublimative coupler to a photosensitive layer from a layer of the coupler formed at the back surface of the original and overlapped on the photosensitive layer may be used as a heat source of the apparatus of this invention. An electric heater, a heating roller, an infrared lamp, a heated jet or a high frequency heater may be optionally used. In order to conduct the heat transfer of the thermovolatile or thermosublimative coupler to the photosensitive layer effectively, it is preferable to prevent the escape of the coupler transferred to the diazo-type photosensitive layer by maintaining the thermovolatile or thermosublimative coupler layer at a temperature higher than that of the photosensitive layer and thus forming a temperature gradient between the two layers. To achieve the above result it is especially preferable to use an infrared lamp. Radiations emitted from an infrared lamp selectively heat images of the original, whereby the thermovolatile or thermosublimative coupler can be effectively heat-transferred to the diazo-type photosensitive layer from portions of the coupler layer corresponding to images. The wavelength of an infrared lamp is not critical, but based on experiments it was confirmed that in order to obtain as many multicolored reproductive copies as possible from one original treated with the thermovolatile or thermosublimative coupler it is most preferred to use an infrared lamp that can radiate sub stantially near infrared rays. Also these heat sources may be contained in a rotatable cylinder in which they are contacted with a piled assembly of the original, the coupler layer and the photosensitive layer.

A piled assembly of the original, the coupler layer and the photosensitive layer may be subjected to actions of the light source and heat source coincidentally. Alternatively, it may be exposed at first to light by means of the light source and then heated by means of the heat source to effect the heat transfer. It is also possible to effect the heat transfer by means of the heat source first, followed by the light exposure by the light source.

The light source and heat source may be contained in a unit transparent cylinder. In this case, a cold air duct of a semicylindrical form is fixed to a frame of the apparatus and a partition plate is provided on the reflecting surface of the cold air duct. In two chambers defined by partition plate, heat and light sources are separately provided to approximate to the cylinder surface. It is also possible to provide heat and light sources in two separate rotatable transparent cylinders or to provide only the light source in a transparent cylinder and to effect the heat transfer at a different place by means of a heating roller or a heated jet.

The diazo-type photosensitive material which has been exposed to light and on which the coupler has been heattransferred, is separated from the original and coupler layer, and it is fed alone to the development mechanism where it is developed. The development mechanism may be of either dry or wet type. In the case of the dry development, a developer mechanism of such a structure is used that a heated mixture of ammonia and steam is uniformly contacted with the photosensitive material. In the case of the wet development, a development mechanism in which a liquid developer for the wet development is coated on the photosensitive material by means such as roller coating, dipping coating and spraying is generally used.

The delivery mechanism comprises a device for subjecting the photosensitive material, the coupler layer and the original to actions of the light source and heat source, for instance, an endless belt driven in contact with a rotatable transparent cylinder, and a moving endless belt or at least one pair of rollers provided in contact with, or in proximity of, the development mechanism. The original, the thermovolatile or thermosublimative coupler layer and the diazo-type photosensitive layer overlapped in this order are allowed to pass through a passage formed between the endless belt and the light-exposure and heattransfer zone Where they are subjected to actions of the heat and light sources, whereby the photosensitive layer is exposed and the coupler is heat-transferred on the photosensitive layer, after which the photosensitive layer is forwarded from the light-exposure and heat-transfer zone, separated from the original and coupler layer manually or by suitable means, and then delivered to the development mechanism by means of an endless belt or rollers.

In this invention it is preferable to reduce the Heat given to the endless belt to a minimum degree possible. Therefore, it is desired to provide a suitable cooling member or to select such material or color of the endless belt as being not easily heat-receivable.

In the embodiment illustrated in FIG. 3, in a rotatable, transparent cylinder 1 a cold air duct 3 one of whose walls constitutes a reflective plate 2 is provided. On the opposite side of the reflective plate 2 of the cold air duct two chambers are provided defined by a reflective partition 4. In these chambers a light source 5 consisting of a high voltage mercury lamp and a heat source 6 consisting of an infrared lamp radiating substantially near infrared rays are mounted; respectively. Each of the light source and heat source 6 is fixed to the reflective plate via a suitable supporting member. On the circumferential wall of the cold air duct 3 a hole-like or slit-like slot or the like is formed through which the cold air fed from one or both ends of the duct is projected to the inside of the cylinder. Thus, the cold air cools the light source 5 and the cylinder wall, and then is discharged from the side opposite to the duct. An endless belt 11 is mounted in the ]-figured form through rollers 7, 8, 9 and 10. The endless belt 11 is driven by means of, for instance, roller 7 and/or roller 10. By the movement of the endless belt 11, the cylinder 1 rotatably supported on the apparatus frame is also rotated. On the feed side of the endless belt 11 a paper-feeding table 12 may be provided, and an original receiving saucer may be provided on the discharge side of the endless belt 11.

It is desired to prevent the endless belt 11 as much as possible from being heated. For this purpose, it is possible to select the material or color of the endless belt as one which is not easily heat-receivable and/or to cool the endless belt 11 by providing between rollers 8 and 9 a cooling duct 14 with an opening for projecting the cold air fed from a fan 15. Of course, it is also possible to maintain the temperature of the endless belt at low levels by cooling the roller 8 with a suitable cooling medium instead of providing such cooling duct.

Another endless belt 16 is provided between rollers 17 and 18 in the position adajcent to the endless belt 11 and contacting a developer 19. The endless belt 16 is driven by means of a roller 18 at the rate synchronized with the endless belt 11. In the developer 19 a plate 20 for evaporating aqueous ammonia and an evaporation heater 21 are provided. The gasified ammonia and steam are introduced onto photosensitive layer through a plurality of openings formed on a wall 22 of the endless belt 16. It is possible to provide a saucer 23 for receiving reproductive copies on the discharge side of the endless belt 16.

When the reproduction is conducted by using the abovementioned apparatus of this invention, as is shown in FIGS. 1 and 2, an original (A) on which is formed a layer of a thermovolatile or thermosublimative coupler is piled on a diazo-type photosensitive material (B), and an assembly of (A) and (B) is fed to a passage between the cylinder 1 and the endless belt 11, exposed to light by means of the light source 5 and heated by means of the heat source 6. The original (A) and the photosensitive material (B') on which the coupler has been transferred are discharged from between the cylinder 1 and the endless belt 11 and the original (A) is received on the saucer 13, while the photosensitive material (B') is manually separated from the original (A), placed on the endless belt 11 and introduced into a passage formed between the endless belt 16 and the wall 22 of the developer where it is allowed to contact with gasified ammonia and steam and thus be developed. The developed copy (C) is received on the saucer 23.

It is also possible to effect the heat transfer of the coupler at first and then the light exposure by providing, as is shown in FIG. 4, a heat source 6 consisting of an infrared lamp in the lower portion of the cylinder 1 and a light source 5 consisting of a high voltage mercury lamp in the upper portion of the cylinder 1.

FIG. 5 illustrates an embodiment in which light source 5 and heat source 6 are provided separately. In the cylinder 1 a light source 5 consisting of an ultraviolet lamp is mounted on a reflective plate 2, and in another cylinder 1' a heat source 6 consisting of an infrared lamp is provided.

The endless belt 11 is driven by means of, for instance, rollers 7 and and is rotated while being in contact with the cylinder 1 to rotate the same. Then, the endless belt 11 falls in contact with the cylinder 1 to rotate the same, and passes through rollers 10 and 9, a cooling zone, and rollers 8 and 8' in this sequence. Instead of the infrared 12 lamp 6 and cylinder 1' a hot wheel 1' provided with an electric heater as the heat source, may be used. The function and operation of each member are the same as in the embodiment shown in FIG. 1.

FIG. 6 illustrates an embodiment of the wet develop merit mechanism using a liquid developer. A photosensitive material (B') which has been exposed to light and on which the coupler has been transferred is dipped in a liquid developer (D) contained in a liquid developer tank 19, and is allowed to pass through rotating roller 24 and developing roller 25 by which the liquid developer is coated on the photosensitive material (B') and the development thereof is effected. The developing roller is formed of a material capable of maintaining thereon the liquid developer conveyed by the roller 24 and applying it to the photosensitive surface of the photosensitive material (B'), such. as a multicellular material. In an embodimental shown in FIG. 7, the photosensitive material (B') which has been exposed to light and on which the coupler has been heat-transferred is dipped in the liquid developer contained in a developing saucer 19 by means of a pair of paper-feeding rollers 17 and 17, and is developed. Then, the developed photosensitive material (B') is allowed to pass through a pair of squeezing rollers 18 and 18' and discharged in the form of a copy. In embodiments shown in FIGS. 6 and 7, roller 24, developing roller 25, paperfeeding rollers 17 and 17, and squeezing rollers 18 and 18' should be driven at a superficial speed synchronized with the endless belt running through the light-exposure and heat-transfer zones.

In an embodiment of the apparatus of this invention shown in FIG. 8, a roller 10 for supporting and rotating the endless belt 11 is provided in the direction almost vertical to the cylinder 1. Between the cylinder 1 and the roller 10 a suction chamber 30 is disposed contacting the back surface of the endless belt 11. A plurality of openings are formed on the wall 31 of the suction chamber 30 contacting the belt 11. On the opposite side of the endless belt 11 another suction chamber 28 is disposed to confront the suction chamber 30. In this suction chamber 28 a curved wall 29 having a plurality of openings is formed. At the other end of the suction chamber 28, rollers 26 and 26 are provided. An endless belt 32 is hung on the roller 26' and the suction chamber 28, and the belt 32 is driven by the driving roller 26' at a rate synchronized with the endless belt 11. The original (A) and the photosensitive material which has been exposed to light and on which the coupler has been heat-transferred is introduced into a passage formed between the driving belt 11 and the belt 32, and the original (A) is sucked to the belt 32 through perforations or openings of the belt 32 and received on a saucer 13 via rollers 26 and 26, while the photosensitive material (B') is sucked toward the suction chamber 30 through perforations or openings of the belt 11, allowed to move upwardly in the state adhering to the belt 11, and to pass through a passage between a guiding plate 33 and the belt 11, and delivered to the development mechanism while being gripped by a roller 27.

In the apparatus of the above type, the separation of the original from the photosensitive material which has been exposed to light and on which the coupler has been heattransferred can be achieved automatically, and the photosensitive material can be automatically fed to the development mechanism. Further, the belt 11 is cooled by the suction mechanism provided adjacently thereto. Accordingly, the apparatus of this type is very advantageous.

FIG. 9 illustrates an embodiment similar to that shown in FIG. 8, except that light source 5 and heat source 6 v are provided in cy linders 1 and 1', respectively.

Also in the apparatuses shown in FIGS. 8 and 9, it is possible to adopt other development mechanisms described with respect to the apparatuses shown in FIGS. 6 and 7.

In the apparatus of this invention, it is preferable to provide a mechanism for controlling the temperatures of a cylinder glass and a delivery belt. A suitable temperature 13 control mechanism adoptable in this invention is illustrated in the block diagram of FIG. 10. A temperaturedetecting member such as a thermocouple or a thermistor is provided adjacent to the glass cylinder containing light and heat sources or in contact therewith. A cold air duct such as described hereinabove is provided in the cylinder glass and the cooling of the cylinder glass may be effected and adjusted by the changeover of a motor switch of a cold air-feeding fan or by means of a throttle valve mounted on a duct of the fan. It is also possible to provide the delivery belt with a cooling mechanism such as described above. Since the delivery belt falls in contact with the cylinder glass, the temperature of the delivery belt is the same as, or a little lower than, the temperature of the cylinder glass. A certain range of the temperature is prescribed with respect to the cylinder glass depending on the kind of original and thermovolatile or thermosublimative coupler (for instance, optionally selected from temperatures ranging from 60 to 150 C.), and when the temperature of the cylinder deviates from such prescribed range, the cooling mechanism for the cylinder glass, optionally together with the cooling mechanism of the delivery belt, is adjusted so as to control a further increase of the temperature. Thus, the temperatures of the cylinder and delivery belt can be maintained at a certain prescribed level. Further, since the heat-transferable coupler layer which is positioned between the cylinder glass and delivery belt is more greatly heated by means of a heat source such as an infrared lamp, among the coupler layer, the photosensitive layer and the delivery belt, a temperature gradient suitable for the effective heat transfer can be obtained. In order to keep the temperature of the coupler layer at an optimum condition for the heat transfer, it is possible to provide a device for adjusting the electric voltage of the heat source or a sector for adjusting amounts of infrared rays to be radiated. In order to make the apparatus of this invention applicable also to an ordinary diazotype monochromatic reproduction process, it is desired to provide separately a changeover switch for the heat source.

In accordance with this invention it is possible to obtain copies in which predetermined portions are clearly colored in different hues, and further, the multicolor development can be effected only by one developing step. Still further, in case the original is once treated, at least sheets, generally 20 to 100 sheets, of multicolored reproductive copies can be obtained from the original. Accordingly, it is unnecessary to repeat the treatment of the original for every one copy. Still in addition, in this invention the treated original for multicolor development can be easily restored into the former untreated condition by peeling off the sheet of the heat-transferable coupler or by subjecting the coupler-coated original to a mere heat treatment at about 100 C.

The reproduction process of this invention is particularly advantageous for reproducing important or significant portions of originals such as papers, drawings and charts into hues different from those of other portions and is effective for obtaining ordinary multicolor copies or colored copies.

This invention will be described hereinbelow by referring to examples.

EXAMPLES OF THE PREPARATION OF INKLIKE AGENTS FOR TREATING THE BACK SURFACE OF AN ORIGINAL Example A An ink-like composition of the following recipe is prepared as a yellow color-forming agent for treating the back surface of an original:

Acetoacetic anilide g 20 Alkyd resin g 5 T oluol ml 100 Example B An ink-like composition for treating the back surface of an original, which resembles that of Example A, is prepared by using acetoacetic-o-chloroanilide instead of acetoacetic anilide in Example A.

Example C An ink-like composition of the following recipe is prepared as a red color-forming agent for treating the back surface of an original:

Resorcin g 20 Vinyl acetate resin g 5 Methanol ml The above composition is directly used as a material to be coated on the back surface of a portion of the original to be reproduced in red to brown by means of a brush, a coating roller or a sprayer, or after it has been charged in a felt pen or a ball pen, it is used as a material for treating the back surface of a portion of the original to be reproduced in red to brown.

Example D A treating agent for forming a red-to-orange color is prepared by using o-amino-phenol instead of resorcin in Example C.

Example E An ink-like composition of the following recipe is prepared as a blue color-forming agent for treating the back surface of an original:

2,3-dihydroxynaphthalene g 15 Modified styrene resin g 5 Ethanol l 100 The above composition is directly used as a material to be coated on the back surface of a portion of the original desired to be reproduced in blue by means of a brush, a coating roller or a sprayer, or after it has been charged in a felt pen or a ball pen, it is used as a material for treating the back surface of a portion of the original desired to be reproduced in blue.

Example F A treating agent similar to that of Example E is prepared by using 2,7-naphthylene diamine instead of 2,3-dihydroxynaphthalene in Example E.

EXAMPLES OF THE PREPARATION OF WAXY AGENTS FOR TREATING THE BACK SURFACE OF AN ORIGINAL Example G A waxy composition to be used as a yellow color-formmg agent for treating the back surface of an original is prepared by heat melting:

G. Acetoacetic anilide 30 Stearic acid 100 Parafiin 50 Terra alba 50 Diatomaceous earth 20 and solidifying the melt.

The above composition is molded into a crayon sticklike form and is used as a material to be coated on the back surface of a portion of the original desired to be reproduced into a different hue.

15 Example H To the composition of Example G are added 100 g. of mineral oil, 50 g. oleic acid and 20 g. of Aureamine, and the mixture is kneaded in a bowl mill to disperse additional components uniformly. Then, the kneaded mixture is coated on a substrate such as paper to obtain a pressuresensitive copy sheet. The so formed copy sheet is overlapped on the back surface of an original and the pressing is effected thereon by means of a typewriter or other writing means. Thus, the sheet is used as a material for forming a layer of the waxy agent on the back surface of an image of the original to be reproduced in a different hue.

Example I A waxy composition to be used as a red color-forming agent for treating the back surface of an original is prepared by heat melting G. Resorcin monoglycol ether 20 Paraifin 50 Terra alba 70 Haze wax 20 Stearic acid 100 Magnesium carbonate 20 and solidifying the melt.

The so formed composition is molded into a crayon stick-like or chalk-like form and is used as a material for coating the back surface of a portion of an original desired to be reproduced in a different hue.

Example I A waxy composition of the following recipe is prepared as a blue color-forming agent for treating the back surface of an original:

G. 2,3-dihydroxynaphthalene 50 Stearic acid 100 Paraffin 50 Diatomaceous earth 30 Haze wax 20 The above composition is molded into a crayon sticklike or chalk-like form and is used as a material for coating the back surface of a portion of the original desired to be reproduced in a different hue.

Example L To the composition of Example K are added 100 g. of mineral oil, 30 g. of oleic acid, 20 g. of Oil Blue and 50 ml. of ethanol, and the mixture is kneaded in a bowl mill, coated on a substrate such as paper and dried to obtain a pressure-sensitive copy sheet. This sheet is used as a material for forming a layer of the waxy agent on the back surface of an original in a manner as described in Example H.

EXAMPLES OF THE PREPARATION OF COUPLER- TRANSFERRING SHEETS FOR TREATING THE BACK SURFACE OF AN ORIGINAL Example M A composition of the following recipe is prepared as a yellow color-forming agent for treating the back surface of an original:

Acetoacetic acid aniline g 20 Triacetate resin g Methanol ml 30 Acetone ml 30 Example N A composition to be used as a red color-forming agent for treating the back surface of an original is prepared by using resorcin instead of acetoacetic acid aniline in Example M. From this composition there is formed a sheet for heat-transferring the coupler capable of forming a red color.

Example 0 A composition to be used as a blue color-forming agent for treating the back surface of an original is prepared by using 1,6-dihydroxynaphthalene instead of acetoacetic acid aniline in Example M. From this composition there is formed a heat-transferable sheet capable of forming a blue color.

Example P A waxy composition of the following recipe is used as a black color-forming agent for treating the back surfac of an original:

G. Mineral oil Diatomaceous earth 50 Stearic acid 30 Resorcin 10 Acetoacetic anilide 20 Carbon black 30 Alkali Frex Blue 5 The above composition is well kneaded in a bow mill, coated on a substrate such as paper and dried to form a pressure-sensitive copy sheet. The sheet is used as a material for forming a layer of the waxy composition on the back surface of the original in a manner as described in Example H.

EXAMPLE 1 Multicolor-forming diazo-type photosensitive paper in use for wet development 10 g. of a double salt of 4-diazo-2,S-diethyloxybenzoylaniline chloride-V2 ZnCl 8 g. of citric acid, 0.1 g. of Patent Blue and 10 g. of dextrin are successively dissolved in water, to make 1 liter of a solution. The solution is coated on a base paper and dried to obtain a diazo-type photosensitive sheet for wet development. The photosensitive paper is overlapped on an original in which a portion is treated with the treating material prepared in Example A and another portion is treated with the treating material prepared in Example C. Then, the assembly is heated and printed by means of a mercury lamp and de- Thus, a clear multicolor reproductive copy in which a portion corresponding to the portion treated with the treating material prepared in Example A is colored in yellow, a portion corresponding to the portion treated 17 with the treating material of Example C is colored in red and other portion corresponding to the non-treated portion is colored in bluish violet is obtained.

EXAMPLE 2 same manner as in Example 1, a multicolor reproductive copy similar to that obtained in Example, 1 is obtained.

EXAMPLE 3 Multicolor-forming diazo-type photosensitive paper in use for dry development A solution of the following recipe is prepared:

G. 4 diazo N ethyl-N-B-hydroxyethylaniline chloride- /z ZnCl l Ethylene glycol 50 Citric acid 20 Bis- [5-hydroxy-7-sulfonaphthyl(2) amine Zinc chloride 40 Thiourea 30 Patent Blue 0.1 Water Balance Total1 liter.

The solution is coated on a base paper by a customary coating procedure such as using an air knife coater and dried to form a photosensitive sheet.

The sheet is overlapped on an original in which the back surface of a portion is treated with the treatingmaterial prepared in Example B, the back surface of another portion is treated with the treating material prepared in Example C and the back surface of still another portion is treated with the treating material obtained in Example E. Then, the assembly is heated and exposed to light by means of a mercury lamp to form a latent image of the diazonium salt.

Next, the so treated sheet is subjected to development with gasified ammonia and steam. Thus, a clear multicolor copy in which a portion corresponding to the portion treated with the material of Example B is colored in an orange color, a portion corresponding to the portion treated with the material of Example C is colored in reddish brown, a portion corresponding to the portion treated with the material of Example E is colored in bluish violet, and other portion corresponding to the untreated portion is colored in dark blue is obtained.

EXAMPLE 4 When Example 3 is repeated by. using N,N-[1-hydroxy- 3-sulfonaphthyl(6)] thiourea instead of bis-[S-hydroxy- 7-sulfonaphthyl(2)] amine, a multicolor reproductive copy similar to that of Example 3 is obtained.

EXAMPLE 5 Multicolor-forming photosensitive paper in use for dry development A solution of the following recipe is prepared:

Totall liter.

In the same manner as in Example 1,.a photosensitive paper is prepared from the above solution. The photo- 18 sensitive paper is overlapped on an original in which the sheet for heat-transferring the coupler prepared in Example N is made to confront a part of the back surface of the original. The assembly is exposed to light and heated by means of a mercury lamp. Then, the so treated sheet is subjected to development with gasified ammonia and steam. Thus, a clear two-color reproductive copy in which a portion corresponding to the portion of the original which has been made to confront to the heattransfer sheet is colored in reddish brown and other portion corresponding to the untreated portion of the original is colored in blue is obtained.

EXAMPL 6 The-photosensitive sheet of Example 6 is placed on an original, a part of the back surface of which is treated with the waxy composition obtained in Example G and another part of the back surface of which is treated with the treating material obtained in Example I. A mercury lamp is placed above the assembly and it is exposed to light and heated to form a latent image of the diazonium salt. Whenthe development is effected with gasified ammonia and steam, a clear multicolor reproductive copy in which a portion corresponding to the portion of the original treated with the material of Example G is colored in yellow, a portion corresponding to the portion treated with the material of Example I is colored in reddish brown and a portion corresponding to the untreated portion of the original is colored in dark blue is obtained.

EXAMPLE 7 Multicolor-forming photosensitive paper in use for either wet or dry development A solution of the following recipe is prepared:

4 diazo 2,5 dibutoxy N-phenyl morpholine- /z ZnCl 15 Citric acid 30 Diethylene glycol 20 B Hydroxynaphthoic acid aminoethyl amine (hydrochloride) l0 Thiourea 40 Zinc chloride 30 Patent Blue 0.1

Water Balance Total1 liter.

G. Potassium carbonate 30 Sodium thiosulfate 40 Sodium bicarbonate 30 Potassium tetraborate 5 Activating agent 0.5 Water Balance Total1 liter.

Thus, a clear two-color reproductive copy in which a portion corresponding to the portion of the original treated with the material of Example C is colored in reddishbrown is obtained.

19 EXAMPIJE s Multicolor-forming film A solution of the following recipe is prepared:

The solution is coated on a polyester film by a rod coater and dried at a relatively low temperature (40-50 C.) by warm air to form a photosensitive film. The film is piled on an original in which a part of the back surface of an original image is treated with the ink-like agent prepared in Example A and the back surface of another part of the original image is treated with the treating agent prepared in Example C. The assembly is exposed to light by a mercury lamp and heated and printed. The photosensitive film containing a latent image of the diazonium salt is developed with gasified ammonium and steam. Thus, a clear reproductive copy in which a portion corresponding to the part treated with the treating material of Example A is colored in yellow, a portion corresponding to the part treated with the treating material of Example C is colored in reddish brown, and other portion corresponding to the untreated part of the original is colored in blue is obtained.

EXAMPLE 9 The photosensitive sheet obtained in Example 3 is overlapped on an original in which at one part a pattern is formed by using the waxy treating agent obtained in Example H and effecting pressing by a typewriter or other writing tool, at another part another image is formed as above with the use of the treating agent obtained in Example I, and still another pattern is formed at still another part according to an ordinary pattern-forming procedure. The assembly is heated and exposed to light by means of a mercury lamp to form a latent image of the diazonium salt, followed by development with gasified ammonium and steam. Thus, a clear multicolor reproductive copy in which a portion corresponding to the part where the pattern has been formed with the treating material of Example H is colored in yellowish brown, a portion corresponding to the part where the pattern has been formed with the treating material of Example I is colored in reddish brown and a portion corresponding to the part where the pattern has been formed in a customary manner is colored in dark blue is obtained.

What we claim is:

1. A process for multi-color reproduction, which comprises:

(A) exposing image-wise a diazo-type photosensitive material to actinic light by exposing through an original sheet of an assembly, said assembly consisting of (i) an original sheet having opaque image areas and transparent non-image areas on one surface and a layer containing at least one thermovolatile or sublimable azo 'coupler (a), said layer being on the opposite surface of said original'sheet, and coupler .(a) being located in only preselected areas which are contiguous with opaque image areas of said original sheet, said preselected areas being present in only a portion of the areas contiguous with said opaque image areas of said original sheet, and (ii) a diazo-type photosensitive material having a photosensitive layer containing at least one photosensitive diazonium salt (c), an acidic stabilizer and an azo coupler (b) having a substantially lower rate of coupling with the diazonium salt (c) under the developing conditions than that of the azo coupler (a), said original sheet (i) being superposed on said diazo-type photosensitive material ,(ii) so that the layer of the azo coupler (a) comes into face-to-face contact with the photosensitive layer;

(B) heating said assembly to thereby heat-transfer said layer of the coupler (a) to the corresponding position on the surface of said photosensitive layer, said steps (A) and (B) being performed simultaneously or in the time sequence of (A) to (B) or (B) to (A); and

(C) contacting the exposed photosensitive material with a mixture of ammonia and steam or an alkalicontaining aqueous liquid developer to thereby develop said photosensitive material, whereby in the unexposed latent image area of the portion to which the coupler (a) has been heat-transferred, a dye (c)(a) having a certain hue or color is formed by the selective reaction of the heat-transferred coupler (a) with the diazonium salt (c) and at the same time, in the unexposed latent image areas to which the coupler (a) has not been heat-transferred, a dye (c)-(b) having a different hue or color from said dye (c)-(a) is formed by the reaction of the coupler ,(b) with the diazonium salt (0), thus producing a multi-colored copied image.

2. The process of claim 1 wherein said coupler (a) is applied to the opposite surface of the original.

3. The process of claim 1 wherein said coupler (a) is applied in the form of a composition comprising from 5 to 25% by weight of said coupler (a), 0 to 3% by weight of a colorant, 0 to 5% by weight of a binder, 0 to 2% by weight of a dispersant and the balance an organic solvent.

4. The process of claim 1 wherein said coupler (a) is applied in the form of a composition comprising 5 to 25% by weight of the coupler (a), to 15% by weight of a wax, 10 to 40% by weight of an oil and 0 to 20% by weight of a colorant.

5. The process of claim 1 wherein said coupler (a) is on a transparent transfer sheet disposed between said original and said photosensitive sheet.

6. The process of claim 1 wherein said coupler (a) is a compound free of sulphonic acid groups and selected from a phenol compound, a hydroxynaphthalene compound, an aniline compound and a compound containing an active methylene group.

7. A process for multi-color reproduction, which compnses:

(A) exposing image-wise a diazo-type photosensitive material to actinic light by exposing through an original sheet of an assembly, said assembly consisting of (i) an original sheet having opaque image areas and transparent non-image areas on one surface and a layer containing at least one thermovolatile or sublimable azo coupler (a), said layer being on the opposite surface of said original sheet, and coupler (a) being located in only preselected areas which are contiguous with opaque image areas of said original sheet, said preselected areas being present in only a portion of the areas contiguous with said opaque image areas of said original sheet, and (ii) a diazotype photosensitive material having a photosensitive layer containing at least one photosensitive diazonium salt (0), said original sheet (i) being superposed on said diazo-type photosensitive material (ii) so that the layer of the azo coupler (a) comes into faceto-face contact with the photosensitive layer;

(B) heating said assembly to thereby heat-transfer said layer of the coupler (a) to the corresponding position on the surface of said photosensitive layer, said steps (A) and (B) being performed simultaneously or (in the time sequence of (A) to (B) or (B) to (A); an

(C) thereafter developing the exposed photosensitive layer with an alkaline aqueous liquid developer containing a coupler (b), wherein said coupler (a) has a higher coupling rate under developing conditions than said coupler (b), whereby in the unexposed latent image area of the portion to which the coupler (a) has been heat-transferred, a dye (c)-(a) having a certain hue or color is formed by the selective reaction of the heat-transferred coupler (a) with the diazonium salt (c) and at the same time, in the unexposed latent image areas to which the coupler (a) has not been heat-transferred, a dye (c)-(b) having a difierent hue or color from said dye (c)-(a) is formed by the reaction of the coupler (b) with the diazonium salt (c), thus producing a multi-colored copied image.

8. The process of claim 7 wherein said coupler (a) is applied to the opposite surface of the original.

9. The process of claim 7 wherein the coupler (a) is applied in the form of a composition comprising from 5 to 25% by weight of the coupler (a), to 3% by weight of a colorant, 0 to by weight of a binder, 0 to 2% by weight of a dispersant and the balance an organic solvent.

10. The process of claim 7 wherein the coupler (a) is applied in the form of a composition comprising 5 to 25% by weight of the coupler (a), 85 to by weight of a wax, 10 to 40% by weight of an oil and 0 to by weight of a colorant.

11. The process of claim 7 wherein said coupler (a) is on a transparent transfer sheet disposed between said original and said photosensitive sheet.

12. The process of claim 7 wherein said coupler (a) is a compound free of sulphonic acid groups and selected from a phenol compound, a hydroxynaphthalene compound, an aniline compound and a compound containing an active methylene group.

References Cited UNITED STATES PATENTS 3,454,764 7/1969 Collier et a1 9649 X 22 2,789,904 4/1957 Benbrook et a1. 9691 X 2,541,178 2/1951 Slifkin 96'-91 X 2,542,716 2/ 1951 Slifkin 9691 2,659,672 11/1953 Leuch 9649 2,747,999 5/ 1956 Yutzy et a1 9691 X 2,756,144 7/1956 Ravich 9691 X 3,052,542 9/1962 Sulich 9691 X 3,408,192 10/1968 Aebi 9691 X 3,510,336 5/1970 Figov 9649 X 3,520,691 7/ 1970 Scheler et a1 9649 X FOREIGN PATENTS 1,000,151 8/ 1965 Great Britain 9649 686,686 1/1953 Great Britain 9691 R 694,580 7/ 1953 Great Britain 96-49 815,005 6/1959 Great Britain 9691 R OTHER REFERENCES Landau, R. et al.: J. of Photo. Sci., vol. 13, May 1965, pp. 444-451.

Dinaburg, M. S.: Photosensitive Diazo Cpds., 1964, The Focal Press, pp. -54.

Van der Grinten: The Photographic Journal, 1952, vol. 923, pp. 43-48.

Kosar, J.: Light-Sensitive Systems, Wiley & Sons, 1965.

CHARLES L. BOWERS, 111., Primary Examiner US. Cl. X.R. 

